A spasm is an unexpected, violent and involuntary contraction of muscle or group of muscles accompanied by sudden burst of pain which is generally harmless but may interfere with function. It produces involuntary movement and distortion but ceases after a few minutes.
Spasms may occur due to disease, strain or injury to the muscle or nearby tissues. It could also be an impairment of circulation or disturbance of body chemistry which can be confined, severe or fairly generalized.
Painless or localized spasms are called tics. This involuntary movement of muscles, usually of the face, may seem to be a natural reaction or response to a certain stimulus but eventually, it will happen automatically even without any reason at all.

Spasmodic muscle contraction may also be due to a large number of medical conditions, however, including the dystonias.
Muscle spasms occur early after an injury takes place. It is characterized by a tightening of muscles in the area which could be painful at times but not always. Later on, when the basic injury is not fixed, muscle spasms form muscle knots which are painful and become part of the problem. Often times, it is this pain from the muscle knots that pushes a person to seek treatment of the injury.

This is the case with injuries to the neck and back.
Muscle knots, also known as myofascial trigger points in medical term, are abnormal areas within the muscle which cause pain. There is still not much information as to what muscle knots really are. However, doctors made some biopsy test by cutting a piece out of muscle knots and results showed that some abnormal protein deposits seemed to be present in the sample tissue. Some treating practitioners believe that there is excessive connective tissue in these areas, but there is little evidence in the (unfortunately few) studies that have been done to support the idea of excess connective tissue.
The knots form because the spasm keeps the muscle working continuously around the clock which is beyond normal body function. Generally, our bodies move in normal activities with different muscles working in cycles. Since the muscles are not designed for such continuous work, time will come when muscle work overloads and forms these knots. That is why it is important that spasm is treated to help reduce this problem.
Treatment of muscle spasms and muscle knots depends on medical professional who is working most closely to you.

Exercise is an important method to help with muscle spasms and muscle knots. Another helpful treatment is massage therapy to supplement other treatments. However, exercise and massage can become uncomfortable but the patient is expected to feel better later.
Several medications such as Soma (Watson) relax muscles and relieve pain and discomfort associated with strains, sprains, spasms or other muscles injuries. Muscle relaxants like Soma (Watson) are for specific muscle injury and pain and should not be used for general body aches and pains. Discuss Soma (Watson) uses with your doctor.